Sensors in use today are configured to sense different types of parameters. In certain environments, some sensors can be installed within systems to sense specific parameters from an optimal vantage point. For example, speed sensors can be positioned in close proximity to a moving object to detect rotational speed, linear speed, position, motion, proximity, presence, or other parameters. Early sensors include magnetic pick-ups that rely on the principle of variable reluctance (VR). However, these VR sensors are unable to sense rotation of the object at low speeds. Also, these sensors have to be placed extremely close to the moving object in order to sense the effect of object movement with enough strength to create usable output signals. If a sensor is installed too close to an object, however, damage could be caused to the sensor during installation of the sensor or during operation of the moving object.
In order to overcome some of the problems associated with VR sensors, developers have created active VR sensors. Active VR sensors include amplifiers that convert analog sine wave output signals from the VR sensor into digital output signals. Having such an amplifier, a sensor can be placed at a larger distance from the object to be sensed. As this air gap between the sensor and the object being sensed is increased, the likelihood that debris would be lodged between the sensor and the object is reduced. Although the larger air gap results in more reliable signals and there is less chance that damage would be done to the sensor during operation, further improvements can still be made in the field of sensing devices.